Non-ischemic scar underlines ventricular arrhythmias in Kearns-Sayre Syndrome.

Kearns-Sayre Syndrome (KSS) is a rare, mitochondrial disease in which cardiac involvement has been associated with poor prognosis. Although the most common clinical manifestation is progressive conduction system impairment, patients can suffer from ventricular arrhythmias. Yet, they show a high prevalence of sudden cardiac death, whose etiopathological mechanism is not completely understood. Cardiac magnetic resonance (CMR) is a rising tool to detect subclinical heart involvement in many heart diseases and was recently able to detect non-ischemic scar in patients affected by KSS.   We present a case of a 44 years old patient affected by KSS with a long-standing history of ventricular arrhythmias. Despite electrocardiogram and echocardiogram were normal, CMR showed non-ischemic myocardial scar in the basal-mid lateral wall. Ventricular ectopic beats were assumed to origin from this site, according to their morphology. Our case highlights non-ischemic myocardial scar as a possible etiopathological mechanism of ventricular arrhythmias in patients with KSS. The added value of CMR to provide cardiac involvement identification and risk stratification of these patients is also shown.